[Evaluation of segmentary contractility in Chagas' disease by using the integral of the myocardial velocity gradient (myocardial strain) obtained through tissue Doppler echocardiography].

Objective: To quantify the percentage of contractility of different myocardial segments in patients with Chagas' disease by measuring myocardial strain and to assess the differences in the radial and longitudinal ventricular contractile function in the undetermined and dilated forms of chronic chagasic cardiomyopathy as compared with those in a group of healthy individuals.

Methods: The study comprised 39 individuals [20 (51.3%) of the male sex] divided into the following 4 groups: 1) Nl: 17 (43.6%) healthy individuals; 2) Und: 7 (17.9%) patients with the undetermined form of Chagas' disease; 3) C1: 7 (17.9%) patients with the chronic form of Chagas' disease with ejection fraction < 50%; and 4) C2: 8 (20.5%) patients with the chronic form of Chagas' disease with ejection fraction > 50%. After performing baseline echocardiography, Doppler tissue images were recorded to measure myocardial strain in different segments on longitudinal and transversal parasternal, and apical 2- and 4-chamber views.

Results And Conclusion: The percentage of contractility in the different myocardial segments, both the radial and longitudinal components, is greater in healthy individuals than in patients with the chronic form of Chagas' disease, and in those with the undetermined form of the disease as compared with that of chronic chagasic patients with EF < 50%. Left ventricular radial contractility is greater than left ventricular longitudinal contractility in all groups (Nl, Und, and Chronic). The data presented allow us to propose a progressive character of myocardial impairment in patients with Chagas' disease.